Variational Problems: Nonsmooth Penalties and Time Scales

变分问题：非平滑惩罚和时间尺度

• 批准号: 0306260
• 负责人: Vera Zeidan
• 金额: $ 13.6万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0306260&HistoricalAwards=false
• 关键词: Variational; Problems; Nonsmooth; Penalties; Time

Variational problems arise in a variety of disciplines, including engineering, natural resources, and economics. In the school of such optimization models, the class of Optimal Controls occupies an essential position since it stems from applications in a variety of fields. This class is distinguished by the presence of "hard" constraints such as the control and the state constraints. The generalized problem of Bolza, introduced by R.T. Rockafellar, includes under its wing the class of optimal controls. There, constraints are built into the objective function (or Lagrangian) through "nonsmooth penalty" terms. It is observed that better smoothness behavior is displayed by this model's Hamiltonian. The aim of the first part of the research is to complete the study of the generalized Bolza problem from the point of view of its Hamiltonian. The plan is to build a comprehensive second-order optimality theory and a stability analysis when the state constraints are present. The second goal of this research is to launch the study of optimal control problems over "time scales," that is, when the underlying time belongs to a compact set, not necessarily a connected interval. In particular, the aim is to develop necessary and sufficient criteria for optimality. Substantial modification of the latest techniques in continuous- and discrete-time optimal controls and in nonsmooth analysis will be instrumental in achieving the goals of this research.In recent years, systems in which the running time could be continuous or discrete have taken the front row due to their appearance in a wide range of applications. A time model that allows for such a combination and many more is known as a "time scale." This type of model is directly related to "hybrid systems," which occur in population dynamics, automotive electronics, automated systems, air traffic management systems, integrated system design, and multi-media. In these disciplines, one encounters applications that are formulated mathematically as continuous-time optimal control problems with constraints on the input and/or output, or as optimal control problems over time scales. For the former, important questions remain unanswered regarding finding accurate criteria to identify optimal candidates. On the other hand, since the latter is a completely new direction of research, very few results are known and several open questions need to be answered. The aim of this research is to develop criteria that serve in identifying optimal candidates for each of these classes of problems.

变分问题出现在各种学科中，包括工程，自然资源和经济学。 在这类优化模型中，最优控制类占据了重要的地位，因为它源于各种领域的应用。 这个类的特点是存在“硬”约束，如控制和状态约束。 推广的Bolza问题，由R. T. Rockafellar，包括在其翅膀下的最优控制类。 在那里，通过“非光滑惩罚”项将约束内置到目标函数（或拉格朗日）中。 据观察，更好的光滑性行为显示该模型的哈密顿量。 第一部分的研究目的是从广义Bolza问题的哈密顿量的角度完成对广义Bolza问题的研究。 该计划是建立一个全面的二阶优化理论和稳定性分析时，状态约束。 本研究的第二个目标是启动对“时间尺度”上的最优控制问题的研究，也就是说，当基础时间属于一个紧凑的集合，不一定是一个连接的区间。 特别是，我们的目标是制定必要和充分的最优性标准。 连续和离散时间最优控制和非光滑分析的最新技术的实质性修改将有助于实现本研究的目标。近年来，系统的运行时间可以是连续的或离散的已经采取了前列，由于它们的出现在广泛的应用。 一个时间模型，允许这样的组合和更多的是被称为“时间尺度。这种类型的模型与“混合系统”直接相关，它出现在人口动力学、汽车电子、自动化系统、空中交通管理系统、集成系统设计和多媒体中。 在这些学科中，人们遇到的应用程序是数学上制定的连续时间最优控制问题的输入和/或输出的约束，或作为最优控制问题的时间尺度。 对于前者，关于找到准确的标准来确定最佳候选人的重要问题仍然没有答案。 另一方面，由于后者是一个全新的研究方向，已知的结果很少，需要回答几个开放的问题。 本研究的目的是制定标准，在确定最佳候选人为这些类的问题。